Fix Lambda deployment, IAM permissions, and frontend crash

[YounBrand]

Lambda OOM
128MB was insufficient for a Fastify app with a native addon. Increased to 512MB in both Terraform and the live function.

• Fix crash on Dashboard, Budget, and Bank Link pages when budget categories are undefined — all .amount accesses now use optional chaining (?.amount ?? 0) to handle users with partially set budgets

• Fix test suite: use port 8001 for test DynamoDB container to isolate it from the dev instance, resolving InternalFailure on table creation caused by case-insensitive name conflict with existing users tabl

  Changes

  • terraform/lambda.tf — fix IAM policy with correct table names, all tables, and DeleteItem; remove stale AGENT_SERVICE_URL env var; add memory_size = 512; add aws_caller_identity data source
  • client/src/pages/LinkBankPage.tsx — guard undefined budget fields in reduce and render
  • server/package.json — remove unused bcryptjs and @types/bcryptjs

  Manual AWS changes applied outside this PR

  • IAM policy on financial-assistant-api-role updated with correct table names and all tables
  • Proposals DynamoDB table created
  • AGENT_SERVICE_URL removed from Lambda environment variables